The present invention relates to an electric noise absorber attached to a wire of an electronic device for absorbing electric noise which is generated within the device or which enters from the outside into the device through the wire.
As a method for attenuating such noise, it is well-known that magnetic ferrite is attached around a wire to reduce electric noise flowing through the wire.
In a known method, two parts of half ring-shaped ferrite are attached to the wire using an adhesive tape. Since the ferrite is separated into two pieces, the ferrite can be attached to the wire without disconnecting the wire. The ferrite can attenuate electric noise generated in the wire after the electronic device is assembled with the wire. The attenuating effect of the ferrite can be checked on the spot. However, the attachment of the electric noise absorber is a time-consuming work. Once two parts of half ring-shaped ferrite are attached to the wire by placing the adhesive tape around the ferrite, the adhesive tape must be detached from the ferrite to relocate the ferrite, and after relocation new tape must be wound around the wire.
Japan Published Unexamined Utility Model Application No. 63-39997 discloses two parts of half ring-shaped ferrite housed in a retaining case which surrounds the wire in place. The retaining case housing the separated ferrite can be easily attached to the wire, but the retaining case and the ferrite must be configured to engage each other. The retaining case should have resilient members for closely engaging two parts of the ferrite through abutment surfaces of the parts. In addition to the portion for reducing electric noise, the ferrite requires the portions for superimposing the abutment surfaces and for engaging the retaining case. The reduction in size of those portions is a problem with the related-art electric noise absorber.